Part 1 of file descriptor race and deadlock corrections.

File status flags should be shared for dup'ed file descriptors.
However fd_table_entry's should not be shared for dup'ed file
descriptors so they can be independently be closed without
interfering with dup'ed fd's.

- split out file status flags into its own structure
fs_flags to manage sharing of status flags between
dup'ed file descriptors.
- when duplicating a fd, initialize a new fd_table_entry
for the new fd, but share the status flags via status_flags.
- consolidate the code that sets the underlying system fd
to be non-blocking to a new function _thread_fs_flags_init()
- consolidate the code that sets the underlying system
fd back to blocking into a new function _thread_fs_flags_replace()

This change is needed as a prerequisite to the coming race
and deadlock corrections. okay marc@

1 files changed, 3 insertions, 3 deletions

diff --git a/lib/libpthread/uthread/uthread_write.c b/lib/libpthread/uthread/uthread_write.c
index 393b9da65c7..71581d05387 100644
--- a/lib/libpthread/uthread/uthread_write.c
+++ b/lib/libpthread/uthread/uthread_write.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uthread_write.c,v 1.10 2003/12/22 00:33:42 brad Exp $	*/
+/*	$OpenBSD: uthread_write.c,v 1.11 2006/09/22 19:04:33 kurt Exp $	*/
 /*
  * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
  * All rights reserved.
@@ -62,7 +62,7 @@ write(int fd, const void *buf, size_t nbytes)
 	/* Lock the file descriptor for write: */
 	else if ((ret = _FD_LOCK(fd, FD_WRITE, NULL)) == 0) {
 		/* Get the read/write mode type: */
-		type = _thread_fd_table[fd]->flags & O_ACCMODE;
+		type = _thread_fd_table[fd]->status_flags->flags & O_ACCMODE;
 
 		/* Check if the file is not open for write: */
 		if (type != O_WRONLY && type != O_RDWR) {
@@ -73,7 +73,7 @@ write(int fd, const void *buf, size_t nbytes)
 
 		else {
 		/* Check if file operations are to block */
-		blocking = ((_thread_fd_table[fd]->flags & O_NONBLOCK) == 0);
+		blocking = ((_thread_fd_table[fd]->status_flags->flags & O_NONBLOCK) == 0);
 
 		/*
 		 * Loop while no error occurs and until the expected number